Einstein's signature in cosmological large-scale structure

Understand

We show how the non-linearity of general relativity generates a characteristic non-Gaussian signal in cosmological large-scale structure that we calculate at all perturbative orders in a large scale limit.

• Newtonian gravity and general relativity provide complementary theoretical frameworks for modelling large-scale structure in $\Lambda$CDM cosmology; a relativistic approach is essential to determine initial conditions which can then be used in Newtonian simulations studying the non-linear evolution of the matter density.
• Most inflationary models in the very early universe predict an almost Gaussian distribution for the primordial metric perturbation, $\zeta$.
• However, we argue that it is the Ricci curvature of comoving-orthogonal spatial hypersurfaces, $R$, that drives structure formation at large scales.